21) Which of the following statements are true 1. Stress and Pressure are measured in units of Load/Area 2. Intensity of Pressure at a point is same in all directions whereas Stress depends on load and direction. 3. Pressure and Stress are scalar.

22) Poisson's ratio of which of t he following materials is nearly zero.

23) The stress developed in a thin spherical shell (thickness t and diameter D) subjected to an internal pressure P is:

24) Endurance limit depends on 1. Material 2. Size 3. Surface finish 4. Type of loading

25) Shot peening increases the fatigue life of springs because it results in